The high court will hear the minister’s arguments when it considers whether people may be found not to meet the definition of refugee when they could avoid persecution by changing their occupation. Photograph: Nikki Short/AAPImage

The immigration minister, Scott Morrison, has called for a reinterpretation of the refugee convention, arguing the framework outlining countries’ obligations to those fleeing persecution is being used “as a tool by people smugglers to basically run death voyages”.

The high court will hear the minister’s arguments in the context of a 50-year-old Afghan citizen of Hazara ethnicity who arrived in Australia by boat in February 2012 and feared being killed by the Taliban for working as a truck driver carrying construction materials.

The court will consider whether people may be found not to meet the definition of refugee in circumstances where they could avoid persecution by changing their occupation.

A research fellow working in international law at Melbourne Law School, Martin Clark, said if the court found in favour of Morrison, it “would likely expand the range of things that the minister could decide are reasonable to expect of applicants, and on that basis deny those applicants protection in Australia”.

This might allow the government to pay closer attention to hypothetical changes in conduct as an easier way to deny protection, Clark said.

Documents submitted to the court show the man, identified as “SZSCA”, started work as a silver jeweller in 1977 and continued to work as a jeweller until 2001. He moved with his family to Kabul in 2007 and worked as a self-employed truck driver.

The man was stopped by the Taliban in January 2011 and found to be carrying construction materials, accounting to court documents and evidence presented to previous hearings.

SZSCA alleges he was warned to stop carrying construction materials or he would be killed, because the Taliban believed his work was assisting the Afghan government or foreign agencies.

The man left Afghanistan in December 2011, a month after receiving a letter from the Taliban that allegedly outlined a threat to kill him, and arrived in Australia “as an offshore entry person”.

In June 2012 a delegate of the then immigration minister refused to grant SZSCA a protection visa, accepting that he had been threatened by the Taliban once but noting that he had the option of doing other, safer work if he returned.

The man sought a review by the Refugee Review Tribunal, which backed the original decision – suggesting he had long-established skills making jewellery and rejecting the notion that his work as a truck driver was a “core aspect” of his identity, beliefs or lifestyle which he should not be expected to modify or forego.

Lawyers for Morrison have submitted to the high court: “If his position is that he insists upon driving trucks (carrying building materials or not), he is not outside of Afghanistan because of any well-founded fear of persecution – given the safety that the tribunal has found he would have by remaining in Kabul as a jeweller.”

Clark said it was not the first time Australian courts had considered questions of changes to behaviour on return that would likely avoid future persecution.

“A series of cases have been decided relating to people who would be persecuted on the basis of homosexuality, in which courts have held expecting a person to take ‘reasonable steps’ to avoid persecution is the wrong kind of inquiry,” Clark said.

“But the significance of this challenge is whether or not the ‘reasonable’ requirement should apply to considerations that are not closely related to characteristics that are protected by the convention – like political beliefs, religious views, and so on.”

Morrison said the SZSCA case dealt with “a level of specificity and interpretation of the refugee convention which we would argue goes beyond what the obligations are”.

Commenting on the case after a report in the Australian newspaper on Monday, Morrison told radio station 2GB the court would consider the relevance of matters “within a person’s control” such as what sort of job would put them “in a position of exposure”.

“I know a lot of listeners sometimes say why don’t you just get out of the refugee convention, but the difficulty we have got with the convention is not the document itself but how lawyers and others have interpreted it for the last 50-60 years, not just in this country but around the world,” Morrison told the conservative radio broadcaster Ray Hadley.

“Our courts draw on all of their interpretations and what started out being a pretty sensible document over time has had layer upon layer upon layer and it is now being used as a tool by people smugglers to basically run death voyages.”

Clark said Morrison’s comment was “simplistic” as people smugglers were not arguing in Australian courts about the interpretation of the convention.

“Making this point is also unrelated to the SZSCA case,” Clark said.

“As horrible as the deaths at sea issue is, it should be remembered that the government in the SZSCA case is arguing that it should be easier to send people back to countries where, if they act ‘reasonably’, they won’t be killed.

“That does not fit the spirit or purpose of the refugees convention, and whatever one might say about how ‘outdated’ it is, those problems shouldn’t encourage government to send people back to places where they may likely be killed.”